Fat Cat – Custom Fat Bike

Titanium or Steel

The Fat Cat is our custom Fat Bike. The age of the Fat Bike is here, and Zinn Cycles makes exquisite fat bikes in steel or titanium. This bike is fat, takes the fattest tires, and the biggest riders imaginable. If you are tall, we can build you a fat bike. If you are small, we can build you a fat bike. Made with the same high quality construction as our famous titanium and steel mountain bikes, the Fat Cat will handle any terrain that you can dish out. From snow to sand to backcountry, our fat bikes can do it. We can also add S&S Couplings to any Fat Bike frame to make traveling easy. We can build the rear end to fit a 170mm rear axle and 4” tires or a 190mm axle and 5” tires.

Custom Fat Bike

Frame Material Options

Bike fitting

Bike fitting included with every Zinn bike frame

No matter where you live in the world, we will work with you to make sure the fit of your Zinn bike is absolutely perfect. We offer a full service in-house bike fitting for those who can make it to Boulder, Colorado and we also have detailed measurements instructions for those who cannot make it out for an in-house fitting. We are also happy to work directly with a bike fitter in your area, and we offer upgraded 3D bike fittings with Dr. Andy Pruitt at the Boulder RETUL Center.


Zinn Cycles Design Philosophy

Lennard Zinn has been designing and building great bikes of all types for big and tall cyclists, small women, cyclists with injuries, and everyone else since 1982. He is one of the few bike designers in the world that has dedicated his career to improving the performance and durability of big and tall bikes and bikes for women. He has also spent a great deal of time working with Dr. Andy Pruitt to design bikes for cyclists who have suffered from injuries, reduced mobility, knee problems, back problems, neck problems, and many other ailments. There are many more factors to building a big and tall bike than most people understand. It is not as simple as just scaling up a “normal” sized frame and calling it good. When you do that, several things happen to the bike. First, the stretched-out tubes become less stiff, which results in high speed frame shimmy. This is a scary by-product of a poorly designed bike. Second, the added material makes the bike heavier, especially if the builder tries to solve problem number one with just using thicker tubes. Third, without a fork with a long enough steering tube, the handlebars will be far too low for the tall cyclist, causing discomfort in the back, neck, wrists, and arms. Fourth, building a bike for a tall or small rider with average length cranks will make the rider feel unnatural while pedaling. Proportional crank length is at the heart of all of our custom bike designs. We offer cranks from 130mm all the way up to 220mm, so we can properly fit any person in the world, no matter their size. Lennard has developed great frame design concepts to address and solve all of these issues and more. A bike designed by Lennard Zinn will be stiff and strong, while remaining lightweight. It will not shimmy at high speeds, and all of the components will be proportional to the rider. Fit, performance, comfort, and durability will all be superior on a Zinn bike than a bike from any other designer out there. We guarantee it.

Make it a Travel Bike

Add S&S Couplers for easy travel

If you want your bike to be a travel bike, we can add S&S couplings to your frame. If you choose titanium or steel for your frame material, couplers can easily be built into the frame, making it an incredible travel bike that breaks down into sections and fits into an airline regulation travel case. We can do two or four couplers depending on the size of your frame. Bigger bikes need four couplers and smaller bikes can get away with just two. S&S Couplers do not reduce the strength of the frame one bit, in fact, it’s quite the opposite. The Couplings are so well made that they become the strongest point in the tube! Not all bikes can fit completely into an airline regulation case. Bikes like 29ers, Touring bikes with racks and fenders, and e-bikes may or may not fit completely in the case and will require a secondary bag or case to carry some of the parts. Contact us about building your bike with couplers.

Order a bike now

Excited about your new bike? While you are welcome to come to our location for a full fitting, it is not necessary. You can easily follow the instructions for submitting your own measurements by clicking the measurements button below. To start the order process, please click the button below to pay a deposit. We will contact you with further instructions. Once we have your measurements and deposit, we will create a CAD drawing of your bike for you to review.

Custom Fat Bikes


Are you ready
for your
dream bike?